1 files changed, 39 insertions, 3 deletions

diff --git a/llvm/tools/llvm-cov/CodeCoverage.cpp b/llvm/tools/llvm-cov/CodeCoverage.cpp
index baa968820b63..02c0106cbc29 100644
--- a/llvm/tools/llvm-cov/CodeCoverage.cpp
+++ b/llvm/tools/llvm-cov/CodeCoverage.cpp
@@ -80,6 +80,12 @@ private:
   /// directory, recursively collect all of the paths within the directory.
   void collectPaths(const std::string &Path);
 
+  /// Check if the two given files are the same file.
+  bool isEquivalentFile(StringRef FilePath1, StringRef FilePath2);
+
+  /// Retrieve a file status with a cache.
+  Optional<sys::fs::file_status> getFileStatus(StringRef FilePath);
+
   /// Return a memory buffer for the given source file.
   ErrorOr<const MemoryBuffer &> getSourceFile(StringRef SourceFile);
 
@@ -153,6 +159,9 @@ private:
   /// remapped to, when using -path-equivalence.
   Optional<std::pair<std::string, std::string>> PathRemapping;
 
+  /// File status cache used when finding the same file.
+  StringMap<Optional<sys::fs::file_status>> FileStatusCache;
+
   /// The architecture the coverage mapping data targets.
   std::vector<StringRef> CoverageArches;
 
@@ -239,6 +248,27 @@ void CodeCoverageTool::collectPaths(const std::string &Path) {
   }
 }
 
+Optional<sys::fs::file_status>
+CodeCoverageTool::getFileStatus(StringRef FilePath) {
+  auto It = FileStatusCache.try_emplace(FilePath);
+  auto &CachedStatus = It.first->getValue();
+  if (!It.second)
+    return CachedStatus;
+
+  sys::fs::file_status Status;
+  if (!sys::fs::status(FilePath, Status))
+    CachedStatus = Status;
+  return CachedStatus;
+}
+
+bool CodeCoverageTool::isEquivalentFile(StringRef FilePath1,
+                                        StringRef FilePath2) {
+  auto Status1 = getFileStatus(FilePath1);
+  auto Status2 = getFileStatus(FilePath2);
+  return Status1.hasValue() && Status2.hasValue() &&
+         sys::fs::equivalent(Status1.getValue(), Status2.getValue());
+}
+
 ErrorOr<const MemoryBuffer &>
 CodeCoverageTool::getSourceFile(StringRef SourceFile) {
   // If we've remapped filenames, look up the real location for this file.
@@ -249,7 +279,7 @@ CodeCoverageTool::getSourceFile(StringRef SourceFile) {
       SourceFile = Loc->second;
   }
   for (const auto &Files : LoadedSourceFiles)
-    if (sys::fs::equivalent(SourceFile, Files.first))
+    if (isEquivalentFile(SourceFile, Files.first))
       return *Files.second;
   auto Buffer = MemoryBuffer::getFile(SourceFile);
   if (auto EC = Buffer.getError()) {
@@ -404,7 +434,8 @@ std::unique_ptr<CoverageMapping> CodeCoverageTool::load() {
       warning("profile data may be out of date - object is newer",
               ObjectFilename);
   auto CoverageOrErr =
-      CoverageMapping::load(ObjectFilenames, PGOFilename, CoverageArches);
+      CoverageMapping::load(ObjectFilenames, PGOFilename, CoverageArches,
+                            ViewOpts.CompilationDirectory);
   if (Error E = CoverageOrErr.takeError()) {
     error("Failed to load coverage: " + toString(std::move(E)),
           join(ObjectFilenames.begin(), ObjectFilenames.end(), ", "));
@@ -445,7 +476,7 @@ void CodeCoverageTool::remapPathNames(const CoverageMapping &Coverage) {
     SmallString<128> NativePath;
     sys::path::native(Path, NativePath);
     sys::path::remove_dots(NativePath, true);
-    if (!sys::path::is_separator(NativePath.back()))
+    if (!NativePath.empty() && !sys::path::is_separator(NativePath.back()))
       NativePath += sys::path::get_separator();
     return NativePath.c_str();
   };
@@ -709,6 +740,10 @@ int CodeCoverageTool::run(Command Cmd, int argc, const char **argv) {
   cl::alias NumThreadsA("j", cl::desc("Alias for --num-threads"),
                         cl::aliasopt(NumThreads));
 
+  cl::opt<std::string> CompilationDirectory(
+      "compilation-dir", cl::init(""),
+      cl::desc("Directory used as a base for relative coverage mapping paths"));
+
   auto commandLineParser = [&, this](int argc, const char **argv) -> int {
     cl::ParseCommandLineOptions(argc, argv, "LLVM code coverage tool\n");
     ViewOpts.Debug = DebugDump;
@@ -843,6 +878,7 @@ int CodeCoverageTool::run(Command Cmd, int argc, const char **argv) {
     ViewOpts.ShowInstantiationSummary = InstantiationSummary;
     ViewOpts.ExportSummaryOnly = SummaryOnly;
     ViewOpts.NumThreads = NumThreads;
+    ViewOpts.CompilationDirectory = CompilationDirectory;
 
     return 0;
   };